Experts say: Not ‘If’ But ‘When’ For Global Flu Pandemic
By P.J. Heller
In 1918, an influenza pandemic swept the world, infecting an estimated 500 million people and leaving tens of millions of people dead in what has been described as “the greatest medical holocaust in history.”

Now, nearly a century later — despite advances in medicine and science — concerns are being raised about the possibility of another catastrophic global flu pandemic.

“In the next 20 to 30 years, there will be a pandemic and it will have the potential to bring humanity to its knees,” predicted Dr. Larry Brilliant, chair of the Skoll Global Threats Fund, in an interview earlier this year on CNN.

Brilliant, a world-renowned physician and epidemiologist, said a survey he conducted in 2006 of the world’s top epidemiologists found that 90 percent of them thought there would be a pandemic within their children’s or their grandchildren’s lifetime.

“And they thought that if there was a pandemic, a billion people would get sick. As many as 165 million people would die. There would be a global recession and depression as our just-in-time inventory system and the tight rubber band of globalization broke, and the cost to our economy of one to three-trillion dollars would be far worse for everyone than merely 100 million people dying, because so many more people would lose their job and their healthcare benefits, that the consequences are almost unthinkable. And it’s getting worse, because travel is getting so much better,” he said in a 2006 TED talk.

Experts interviewed for this story agree that it’s not a matter of “if” but “when” an influenza pandemic will occur.

“The short answer to your question on the possibility of a flu pandemic is yes,” says Dr. Aileen M. Marty, a professor of infectious diseases in the department of medicine at the FIU Herbert Wertheim College of Medicine in Miami. “There is always a risk of a new flu pandemic.”

“I definitely think we will see another flu pandemic just because of the nature of the virus . . . ” agrees Dr. Michelle A. Barron, medical director, infection control and prevention, at University of Colorado Hospital.

Adds Dr. Timothy Sly, an epidemiologist and emeritus professor at Ryerson University in Toronto: “We seem to experience influenza pandemics of type A influenza two to four times a century. We could see another anytime. It can occur at any time, and could begin anywhere.”

Influenza A is one of three types of flu viruses, the others being Influenza B and Influenza C.

Influenza A viruses infect humans and many different animals, such as avian flu H5N1, H7N9 or H9N2, or swine flu H1N1 or H3N2. Influenza B viruses only circulate among humans and cause seasonal epidemics. Influenza C viruses can infect both humans and pigs, but infections are generally mild and are rarely reported, according to the World Health Organization (WHO).

“Most serious influenza outbreaks have resulted from Influenza A viruses, some from Influenza B viruses, and virtually none from Influenza C viruses,” Marty notes. Among the worst cases since 1918 were flu pandemics in 1957 (H2N2), 1969 (H2N3) and 2009 (H1N1).

Pandemic influenza is always caused by an avian influenza A virus, Sly explains, noting that the 2009 swine flu outbreak “was still essentially an avian influenza.”

Bird flu (H5N1) was first reported in humans in 1997 in Hong Kong.

“Since 2003, this avian virus has spread from Asia to Europe and Africa, and has become entrenched in poultry populations in some countries,” WHO reports. “Outbreaks have resulted in millions of poultry infections, several hundred human cases, and many human deaths.”

In its most recent report, WHO said there have been 859 cases of human infection with the bird flu H5N1 virus, including 453 deaths in 16 countries. It also reported 1,557 cases of human infection with the avian influenza H7N9 virus — first reported in China in 2013 — including at least 605 deaths. Human infection in the majority of all those cases was the result of direct or indirect contact with infected live or dead poultry.

Hundreds of millions of birds have been killed worldwide in an attempt to control the spread of avian flu. Avian flu can be transmitted between infected birds or chickens to humans. Such cases have been reported from about 20 countries worldwide.

However, “a human with avian influenza will not spread it to another bird or chicken or to another human,” Barron notes.

The “nightmare scenario,” Sly says, is if that situation should change and human-to-human transmission becomes possible with people having little to no immunity against the virus.

Such a scenario could occur, he says, if low-pathogenic Influenza A viruses, which are able to circulate easily, interacted with much more deadly avian viruses that have not mutated, allowing the virus to invade the human respiratory tract.

“If genes were re-assorted between these types, for example, then we could emerge with the ‘perfect storm’ — a virus than can spread around the world, and one that is really lethal,” Sly warns. “That is the nightmare scenario.”

Barron and others agree that the big fear is that a virus might mutate, such as acquiring new genes usually from an animal host and its tendency for the virus to make errors when it copies itself.

“In both instances, the flu virus changes enough so that it looks like a brand new virus to humans, and in the absence of a vaccine, there is a worldwide risk of infection and complications,” she says.

Factors which could exacerbate a global flu pandemic today include the greater worldwide population, people living in closer proximity and having the ability to travel the planet quickly and easily. In 2014, for example, Canada reported the first case of human infection with avian flu (H5N1) virus ever detected in North America. The case involved a traveler who had recently returned from China.

“With the growth of global trade and travel, a localized epidemic can transform into a pandemic rapidly, with little time to prepare a public health response,” WHO says.

“Because of the ability to travel long distances in very short periods of time, an individual with the new virus just needs a group of susceptible hosts to pass it on,” Barron says. “We saw this with SARS (Severe Acute Respiratory Syndrome). It likely started in Hong Kong, but very rapidly became a global issue with a major outbreak in the city of Toronto.” Sly agrees.

“When the 1918 influenza was devastating all the countries, it took about six days to cross the Atlantic by ship, longer than the incubation period for the influenza, so theoretically it was easier to spot and contain before the ship docked. That’s where quarantine took place,” he says. “Now, we do the trip in about five to seven hours, much less than the [one to three day] incubation period of influenza. This means a person could fly from Hong Kong or Beijing and be in London, New York, Toronto or Madrid for a day or two before anyone knew they were infected. The potential for transmission in crowded areas anywhere on Earth is much more likely now than 100 years ago.

“Also frozen poultry is shipped from Thailand to just about everywhere daily,” he points out. “It could be that the next pandemic virus started out flying at 35,000 feet in a cargo plane.”

Marty notes that while avian flu can be transmitted from a sick or healthy appearing animal via direct or indirect contact, such as at a live animal market, cooked meat is safe and “people cannot get infected by eating properly cooked meat and food.”

Predicting exactly when the next pandemic will occur or its impact — despite various projections that have been made over the years — is impossible, according to the Centers for Disease Control.

“Traditionally, these avian influenzas seem to originate in Southeast Asia, which may reflect the exceptional amount of avian/human interaction in ‘wet’ markets, but this is by no means a requirement,” Sly says.

Barron agrees, saying the “sky is literally the limit” for where an outbreak could occur.

Barron and Sly disagree, however, on whether a flu pandemic would be as devastating as the one that occurred in 1918.

Sly predicts the pandemic would be worse, based on the number of deaths that occurred in the total number of cases. The 1918 pandemic had a case-fatality rate (CFR) of about 2.5 percent globally, he estimates, meaning that for every 100 people infected, an average of 2.5 people died. The H5N1 virus has a case-fatality rate that has never dropped below 50 percent, he says.

“That’s 20 times more lethal than the 1918 epidemic,” he says. “Clearly, if we were to experience a global pandemic of H5N1 with such a CFR, the results would be catastrophic to an unthinkable degree.

“The H7N9 virus has surpassed the human cases in less than half the time taken by H5N1, and genetically has a greater potential for these last mutations to be made,” he adds. “The human CFR for H7N9 is a bit less, around 33 percent, but even that is still more than 10 times the CFR in 1918. We do need to keep our eye on H7N9.”

Barron, however, says she doesn’t think the number of deaths from a flu pandemic would be as bad as it was in 1918.

“I think we now live in an age where we would be able to quickly identify what the virus was and develop a vaccine while at the same time executing prevention strategies to help contain its spread,” she says. “Also, we are able to give a significant amount of supportive care (fluids, ventilator support, hemodialysis, etc.) that did not exist in 1918.

“I do think we could have more devastation from the perspective of disruption of our daily norms,” she adds. “With the 24-hour news cycle and social media, lots of misinformation is thrown into the mix and can cause unnecessary panic. I think if we look at the recent Ebola outbreak, both scenarios played out. Isolation/containment helped stop the spread of the Ebola virus outside of the initial African countries that were experiencing outbreaks, modern medicine and access to supportive treatment was generally associated with survival, and a vaccine was rapidly developed and appears to be quite effective. In that same notion, there was widespread panic about potential exposure and led to some decisions that in retrospect may have not been appropriate.”

Experts agree that keeping a close watch on flu viruses worldwide is essential.

“To prevent a pandemic, it is important to perform surveillance for these viruses,” Marty says. “Surveillance requires a close collaboration between animal and human sectors and is a combination of event-based sentinel influenza-like illnesses and seve re acute respiratory infections surveillance.”

“ G l o b a l surveillance is a very important step in preventing any type of pandemic, not just one related to flu,” Barron adds. “It has been the key to our ability to contain SARS, MERS (Middle East Respiratory Syndrome) and Ebola.

I strongly believe that we have the ability to forecast what might come next and what we need to do to be prepared for it. We may not have it exactly right, but most of the things we need to do to prepare for the next pandemic would be the same regardless of what the cause turned out to be.”

The CDC says the U.S. government has ongoing efforts to monitor and assess pandemic threats and prepare for an influenza pandemic.

“Because we cannot predict how bad a future pandemic will be, advance planning is needed at the national, state and local level,” it says.

“Whether the planning is for a government entity, a business, school, community-based organization, or healthcare system, all planning efforts should take into consider multiple scenarios of a pandemic (e.g. moderate, severe, or very severe) so that they can be ready to respond quickly and take the appropriate measures to continue daily operations.”

Whether such a response would include a vaccine remains a question. Research has been ongoing into a universal flu vaccine that could be applied every 10 to 20 years, eliminating the need for people to have yearly seasonal flu jabs.

“Vaccines have always been the problem,” Sly says. “Influenza viruses mutate while you watch them. To produce a vaccine today on an emerging new virus could be a complete waste because by the time the virus has mutated to start a pandemic, the vaccine would be only partly effective. But once we wait until the virus has started to spread globally, it can take five to six months to develop a vaccine for that virus, and another six to 10 months or more to produce enough vaccine to dose everyone.”

Barron says advances in science, medicine and technology will all help. “We certainly have much better technology that allows for mass production of vaccines than even 50 years ago,” she says. “Similarly, since most antibiotics were not even in existence 100 years ago, we certainly have significantly more options.”

Even so, Sly warns, “We can never underestimate nature to spring something on us at any time.”

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